TY - JOUR
T1 - Restoration of testis function in hypogonadotropic hypogonadal mice harboring a misfolded GnRHR mutant by pharmacoperone drug therapy
AU - Janovick, Jo Ann
AU - Stewart, M. David
AU - Jacob, Darla
AU - Martin, L. D.
AU - Deng, Jian Min
AU - Stewart, C. Allison
AU - Wang, Ying
AU - Cornea, Anda
AU - Chavali, Lakshmi
AU - Lopez, Suhujey
AU - Mitalipov, Shoukhrat
AU - Kang, Eunju
AU - Lee, Hyo Sang
AU - Manna, Pulak R.
AU - Stocco, Douglas M.
AU - Behringer, Richard R.
AU - Conn, P. Michael
PY - 2013/12/24
Y1 - 2013/12/24
N2 - Mutations in receptors, ion channels, and enzymes are frequently recognized by the cellular quality control system as misfolded and retained in the endoplasmic reticulum (ER) or otherwise misrouted. Retention results in loss of function at the normal site of biological activity and disease. Pharmacoperones are target-specific small molecules that diffuse into cells and serve as folding templates that enable mutant proteins to pass the criteria of the quality control system and route to their physiologic site of action. Pharmacoperones of the gonadotropin releasing hormone receptor (GnRHR) have efficacy in cell culture systems, and their cellular and biochemical mechanisms of action are known. Here, we show the efficacy of a pharmacoperone drug in a small animal model, a knock-in mouse, expressing a mutant GnRHR. This recessive mutation (GnRHR E90K) causes hypogonadotropic hypogonadism (failed puberty associated with low or apulsatile luteinizing hormone) in both humans and in the mouse model described. We find that pulsatile pharmacoperone therapy restores E90K from ER retention to the plasma membrane, concurrently with responsiveness to the endogenous natural ligand, gonadotropin releasing hormone, and an agonist that is specific for the mutant. Spermatogenesis, proteins associated with steroid transport and steroidogenesis, and androgen levels were restored in mutant male mice following pharmacoperone therapy. These results show the efficacy of pharmacoperone therapy in vivo by using physiological, molecular, genetic, endocrine and biochemical markers and optimization of pulsatile administration. We expect that this newly appreciated approach of protein rescue will benefit other disorders sharing pathologies based on misrouting of misfolded protein mutants.
AB - Mutations in receptors, ion channels, and enzymes are frequently recognized by the cellular quality control system as misfolded and retained in the endoplasmic reticulum (ER) or otherwise misrouted. Retention results in loss of function at the normal site of biological activity and disease. Pharmacoperones are target-specific small molecules that diffuse into cells and serve as folding templates that enable mutant proteins to pass the criteria of the quality control system and route to their physiologic site of action. Pharmacoperones of the gonadotropin releasing hormone receptor (GnRHR) have efficacy in cell culture systems, and their cellular and biochemical mechanisms of action are known. Here, we show the efficacy of a pharmacoperone drug in a small animal model, a knock-in mouse, expressing a mutant GnRHR. This recessive mutation (GnRHR E90K) causes hypogonadotropic hypogonadism (failed puberty associated with low or apulsatile luteinizing hormone) in both humans and in the mouse model described. We find that pulsatile pharmacoperone therapy restores E90K from ER retention to the plasma membrane, concurrently with responsiveness to the endogenous natural ligand, gonadotropin releasing hormone, and an agonist that is specific for the mutant. Spermatogenesis, proteins associated with steroid transport and steroidogenesis, and androgen levels were restored in mutant male mice following pharmacoperone therapy. These results show the efficacy of pharmacoperone therapy in vivo by using physiological, molecular, genetic, endocrine and biochemical markers and optimization of pulsatile administration. We expect that this newly appreciated approach of protein rescue will benefit other disorders sharing pathologies based on misrouting of misfolded protein mutants.
KW - Intracellular trafficking
KW - Protein misrouting
KW - Protein trafficking
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U2 - 10.1073/pnas.1315194110
DO - 10.1073/pnas.1315194110
M3 - Article
AN - SCOPUS:84891357083
SN - 0027-8424
VL - 110
SP - 21030
EP - 21035
JO - Proceedings of the National Academy of Sciences of the United States of America
JF - Proceedings of the National Academy of Sciences of the United States of America
IS - 52
ER -